Diagnostic criteria, clinical characteristics, and natural history of Cohen syndrome.

[cohen syndrome]

Cohen syndrome is a rare , recessively inherited condition associated with facial dysmorphism , developmental delay , and visual disability . A delay in making the diagnosis commonly occurs , contributed to by the lack of a definitive molecular test and the clinical variability of published case reports . A specific clinical phenotype has been delineated in a homogeneous cohort of Finnish Cohen syndrome patients , but the applicability of their diagnostic criteria to non-Finnish patients has been debated . Detailed delineation of Cohen syndrome in patients from outside Finland is therefore warranted . We report on the clinical features of 33 non-Finnish Cohen syndrome patients . Variability within the clinical spectrum is identified and the natural history of Cohen syndrome described . Diagnostic guidelines for facilitating accurate and early diagnosis are discussed . Results from molecular genetic analysis using markers located within the previously mapped COH 1 critical region support allelic but not genetic heterogeneity in this UK cohort .